Grading, concept

Residual stresses are often impossible to avoid as a result of manufacturing operations. The graded concept shows, however, that a desired stress state can be designed allowing the dispersion or even optimization of these stresses. Furthermore, the finite element analysis turns... 

Metamorphic facies is a more sophisticated extension of the grade concept to include pressure (i.e., geobarometry) as well as temperature (i.e., geothermometry) in the interpretation of metamorphic rocks. The indicator minerals become groups of minerals or mineral assemblages that characterize a particular region of pressure and temperature. 

Bulk graphites are also used in the HTGR concept to support and surround the active fuel core. These components tend to be large, complex-shaped blocks and have been produced from commercial grades of molded or extmded graphites. 

Fully integrating, for the first time, Chemistry Principles and Reactions with the OWL web-based chemistry learning system and assessment tool. Select end-of-chapter Questions and Problems from this edition are available in OWL with chemical and numeric parameterization, to provide students with a mastery learning environment and online graded homework. These problems are correlated to the Key Concepts summary list at the end of each chapter. OWL is described in more detail later in this Preface. 

Once the performance and environmental conditions have been defined, the selection of a suitable material can be made, and this in turn can be followed, if necessary, with the necessary engineering calculations to establish strength requirements. The basic data needed for calculations have to be collected and have to pertain to the specific grade of the selected material. The pertinent information required for making determinations for longevity of the product and obtaining a general concept of the character and behavior of the selected material should be supplied by the manufacturer of the raw material and/or obtained in-house or via a contractor. 

Schmidt s (1992) investigation of students conceptions (12th grade) concerning isomerism showed that students mostly regard substances from the same material type (acids, ethers) as isomers n-propanol and isopropanol, for example, are regarded as isomers, whereas propanol and ethyl-methylether are not considered to be isomers. In contrast to Schmidt s hypotheses, the shape (rod-like, cross-shaped) of the molecules was not so important for their choice. 

In summary, we found that the students received lower scores on items that were at different pressures than on items with the same amount of pressure. Also, we found that although the students learned the concept of diffusion in their seventh grade biology class, they did not generate the conception of diffusion in a submicro-scopic maimer. Instead, they tended to conceptualize the diffusion of the particles in a more intuitive way (the heavier object sinking to the bottom of the container) than in a scientific model that was designed to delineate the random nature of the particle motion. 

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